Threespine stickleback fish is an emerging model system for studying the developmental genetic basis of quantitative traits. Researchers within the community agree that tools to leverage and enhance the recently completed genomic sequence are essential. We propose to help investigators understand the underlying genetics of the naturally varing traits seen in stickleback by providing to the community a microarray-based system for efficient and cost effective genotyping. The high-throughput genotyping system that we have developed, RAD mapping, will enable the rapid identification of the genes controlling complex traits ranging from behavior to bone shape. In order to facilitate the use of this tool, simple web-accessible array analysis tools and a hands-on course to train researchers new to genomics will be provided. Stickleback are a complementary model system for many laboratory-based organisms, in that the numerous isolated and divergent natural populations have evolved adult traits that are a difficult or impossible to study by traditional mutagenesis approaches. Importantly, many of these traits are quantitative, influenced by alleles at genetic diseases, and stickleback are a unique vertebrate model for examining these quantitiative traits. The genotyping tools that we propose here will greatly accelerate this important research. Investigators from other research communities such as Drosophila, zebrafish, and mouse have expressed enthusiasm for initiating work in stickleback if these proposed tools were available. Thus, our genomic tools will increase the rate of discoveries of the genetic basis quantitative variation that underlies most common human diseases both by assisting present stickleback researchers;and by drawing additional researchers to work on this emerging model organism. Relevance: Most common human diseases, such as heart disease, high blood pressure, and osteoarthritis, are the result of complex interactions between an individual's genes and her or his environment. Threespine stickleback fish are an excellent model for these kinds of traits, and have numerous traits that are similarly controlled by many genes and the particular environment in which they live. We propose to create research tools to enable the rapid discovery of the genes controlling these complex traits, and help further the emergence of stickleback as an important model for common human traits specifically, and complex traits in general.